Field of the Invention
The present invention relates to an apparatus and method of processing substrate which deposits a thin film on a substrate.
Discussion of the Related Art
Generally, in order to manufacture a solar cell, a semiconductor device and a flat panel display device, it is necessary to form a predetermined thin film layer, a thin film circuit pattern or an optical pattern on a surface of a substrate. Thus, a semiconductor manufacturing process may be carried out, for example, a thin film deposition process of depositing a thin film of a predetermined material on a substrate, a photo process of selectively exposing the thin film by the use of photosensitive material, and an etching process of forming a pattern by selectively removing an exposed portion of the thin film.
The semiconductor manufacturing process is performed inside a substrate processing apparatus designed to be suitable for optimal circumstances. Recently, a substrate processing apparatus using plasma is generally used to carry out a deposition or etching process.
This semiconductor manufacturing process using plasma may be a PECVD (Plasma Enhanced Chemical Vapor Deposition) apparatus for forming a thin film, and a plasma etching apparatus for etching and patterning the thin film.
FIG. 1 illustrates a substrate processing apparatus according to the related art.
Referring to FIG. 1, the substrate processing apparatus according to the related art may include a chamber 10, a plasma electrode 20, a susceptor 30, and a gas distributing means 40.
The chamber 10 provides a reaction space for substrate processing. In this case, a predetermined portion of a bottom surface of the chamber 10 is communicated with an exhaust pipe 12 for discharging gas from the reaction space.
The plasma electrode 20 is provided on the chamber 10 so as to seal the reaction space.
One side of the plasma electrode 20 is electrically connected with a RF (Radio Frequency) power source 24 through a matching member 22. The RF power source 24 generates RF power, and supplies the generated RF power to the plasma electrode 20.
Also, a central portion of the plasma electrode 20 is communicated with a gas supply pipe 26 of supplying source gas for the substrate processing.
The matching member 22 is connected between the plasma electrode 20 and the RF power source 24, to thereby match load impedance and source impedance of the RF power supplied from the RF power source 24 to the plasma electrode 20.
The susceptor 30 is provided inside the chamber 10, and the susceptor 30 supports a plurality of substrates W loaded from the external. The susceptor 30 corresponds to an opposite electrode in opposite to the plasma electrode 20, and the susceptor 30 is electrically grounded by an elevating axis 32 for elevating the susceptor 30.
The elevating axis 32 is moved up and down by an elevating apparatus (not shown). In this case, the elevating axis 32 is surrounded by a bellows 34 for sealing the elevating axis 32 and the bottom surface of the chamber 10.
The gas distributing means 40 is provided below the plasma electrode 20, wherein the gas distributing means 40 confronts with the susceptor 30. In this case, a gas diffusion space 42 is formed between the gas distributing means 40 and the plasma electrode 20. Inside the gas diffusion space 42, the source gas supplied from the gas supply pipe 26 penetrating through the plasma electrode 20 is diffused. The gas distributing means 40 uniformly distributes the source gas to the entire area of the reaction space through a plurality of gas distributing holes 44 being communicated with the gas diffusion space 42.
In case of the substrate processing apparatus according to the related art, after the substrate (W) is loaded onto the susceptor 30, the predetermined source gas is distributed to the reaction space of the chamber 10, and the RF power is supplied to the plasma electrode 20 so as to form the plasma in the reaction space between the susceptor 30 and the gas distributing means 40, to thereby deposit a source material of the source gas on the substrate (W) by the use of plasma.
However, the substrate processing apparatus according to the related art may have the following problems.
First, a density of the plasma formed on the entire area of the susceptor 30 is not uniform so that a uniformity of the thin film material deposited on the substrate (W) is deteriorated, and it is difficult to control quality of the thin film.
Also, since the plasma is formed on the entire area of the susceptor 30, a thickness of the source material deposited on the chamber 10 as well as a thickness of the source material deposited on the substrate (W) may be rapidly increased so that a cleaning cycle of the chamber 10 is shortened.